Magovcevic-Liebisch Ivana

SEC source: 0001279281-26-000003 · primarydocument.xml · derivative · entry 2

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,352

Underlying: Common Stock · 4,224 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_date: On October 2, 2024, the reporting person was granted 12,800 restricted stock units, vesting 33%, 33%, and 34% on the first, second, and third anniversaries of the grant date, respectively.

F2 · derivative.expiration_date: On October 2, 2024, the reporting person was granted 12,800 restricted stock units, vesting 33%, 33%, and 34% on the first, second, and third anniversaries of the grant date, respectively.

SEC source: 0001279281-26-000003 · primarydocument.xml · nonDerivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 15,883

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Restricted stock units convert into common stock on a one-for-one basis.

SEC source: 0000905148-26-003034 · form4.xml · derivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,275

Underlying: Common Stock · 20,275 shares

Expires 2036-06-16

F1 · derivative.exercise_date: The shares subject to the option shall vest on the date immediately preceding the date of the Issuer's next annual meeting of stockholders, subject to the Reporting Person's continuous service through the applicable vesting date.

SEC source: 0000905148-26-002559 · form4.xml · nonDerivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,366

F1 · kind: These shares represent restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. These RSUs shall vest in full on May 18, 2027, subject to the Reporting Person's continuous service through such vesting date.

SEC source: 0001279281-26-000001 · primarydocument.xml · nonDerivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 43,607

F1 · shares: Represents restricted stock units that vest as to 100% of the shares on January 2, 2027 granted pursuant to the Quanterix Corporation Amended and Restated Non-Employee Director Compensation Policy. Each restricted stock unit represents the right to receive one share of the Issuer's common stock.

F2 · balance_after: Includes 43,607 restricted stock units.

SEC source: 0000950170-25-102487 · ownership.xml · derivative · entry 9

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 485,000 shares

Expires not disclosed

F1 · kind: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F2 · price: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F2 · derivative.exercise_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F2 · derivative.expiration_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

SEC source: 0000950170-25-102487 · ownership.xml · derivative · entry 8

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 463,000 shares

Expires not disclosed

F1 · kind: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F2 · price: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F2 · derivative.exercise_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F2 · derivative.expiration_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

SEC source: 0000950170-25-102487 · ownership.xml · derivative · entry 7

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 370,000 shares

Expires not disclosed

F1 · kind: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F2 · price: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F2 · derivative.exercise_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F2 · derivative.expiration_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

SEC source: 0000950170-25-102487 · ownership.xml · derivative · entry 6

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 282,000 shares

Expires not disclosed

F1 · kind: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F2 · price: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F2 · derivative.exercise_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F2 · derivative.expiration_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

SEC source: 0000950170-25-102487 · ownership.xml · derivative · entry 5

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 43,271 shares

Expires not disclosed

F1 · kind: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F3 · price: Each stock option having an exercise price per share that is equal to or greater than the Closing Amount but less than $10.00 was cancelled and converted into the right to receive one CVR for each share subject to such option immediately prior to the Effective Time, except that if the milestone is achieved in respect of the CVR, the cash amount to be paid to such option holder will be an amount equal to (i) $10.00 minus (ii) the exercise price per share subject to such option, subject to applicable tax withholdings

F3 · derivative.exercise_date: Each stock option having an exercise price per share that is equal to or greater than the Closing Amount but less than $10.00 was cancelled and converted into the right to receive one CVR for each share subject to such option immediately prior to the Effective Time, except that if the milestone is achieved in respect of the CVR, the cash amount to be paid to such option holder will be an amount equal to (i) $10.00 minus (ii) the exercise price per share subject to such option, subject to applicable tax withholdings

F3 · derivative.expiration_date: Each stock option having an exercise price per share that is equal to or greater than the Closing Amount but less than $10.00 was cancelled and converted into the right to receive one CVR for each share subject to such option immediately prior to the Effective Time, except that if the milestone is achieved in respect of the CVR, the cash amount to be paid to such option holder will be an amount equal to (i) $10.00 minus (ii) the exercise price per share subject to such option, subject to applicable tax withholdings

SEC source: 0000950170-25-102487 · ownership.xml · derivative · entry 4

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 405,494 shares

Expires not disclosed

F1 · kind: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F2 · price: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F2 · derivative.exercise_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F2 · derivative.expiration_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

SEC source: 0000950170-25-102487 · ownership.xml · derivative · entry 3

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 210,629 shares

Expires not disclosed

F1 · kind: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F2 · price: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F2 · derivative.exercise_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F2 · derivative.expiration_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

SEC source: 0000950170-25-102487 · ownership.xml · derivative · entry 2

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 369,351 shares

Expires not disclosed

F1 · kind: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F2 · price: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F2 · derivative.exercise_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F2 · derivative.expiration_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

SEC source: 0000950170-25-102487 · ownership.xml · nonDerivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

F1 · kind: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F1 · price: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

SEC source: 0000905148-25-002171 · form4.xml · derivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,275

Underlying: Common Stock · 20,275 shares

Expires 2035-06-12

F1 · derivative.exercise_date: The shares subject to the option shall vest on the date immediately preceding the date of the Issuer's next annual meeting of stockholders, subject to the Reporting Person's continuous service through the applicable vesting date.

SEC source: 0000950170-25-032406 · ownership.xml · derivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 485,000

Underlying: Common Stock · 485,000 shares

Expires 2035-03-03

F1 · derivative.exercise_date: This stock option award was issued pursuant to the Issuer's 2021 Stock Option and Incentive Plan and shall vest and become exercisable in forty-eight (48) equal monthly installments, with the first installment vesting on April 3, 2025.

SEC source: 0001562180-25-000209 · primarydocument.xml · derivative · entry 2

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 15,821

Underlying: Common Stock · 15,821 shares

Expires 2035-01-02

F3 · shares: Represents non-qualified stock option to purchase 15,821 shares of common stock granted pursuant to the Quanterix Corporation Amended and Restated Non-Employee Director Compensation Policy.

SEC source: 0001562180-25-000209 · primarydocument.xml · nonDerivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,235

F1 · shares: Represents restricted stock units that vest as to 100% of the shares on December 31, 2025 granted pursuant to the Quanterix Corporation Amended and Restated Non-Employee Director Compensation Policy. Each restricted stock unit represents the right to receive one share of the Issuer's common stock.

F2 · balance_after: Includes 20,235 restricted stock units.

SEC source: 0000950170-24-138617 · ownership.xml · nonDerivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 222,687

F1 · price: The price reported in Column 4 is a weighted average price. The shares were purchased in multiple transactions at prices ranging from $1.67 to $1.68, exclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price at which the transactions were effected.

SEC source: 0000950170-24-138012 · ownership.xml · nonDerivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 217,687

SEC source: 0000950170-24-133755 · ownership.xml · nonDerivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 212,687

F1 · price: The price reported in Column 4 is a weighted average price. The shares were purchased in multiple transactions at prices ranging from $2.33 to $2.34, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price at which the transactions were effected.

SEC source: 0001562180-24-007237 · primarydocument.xml · derivative · entry 2

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 27,689

Underlying: Common Stock · 27,689 shares

Expires 2034-10-02

F3 · derivative.exercise_date: The option vests as to one-third of the shares on October 2, 2025, and the remaining two-thirds of the shares vest monthly thereafter over two years in 24 successive equal installments.

SEC source: 0001562180-24-007237 · primarydocument.xml · nonDerivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 12,800

F1 · shares: Represents shares of stock issuable on vesting of restricted stock units. The restricted stock units vest as to one-third of shares on each of October 2, 2025, October 2, 2026 and October 2, 2027.

F2 · balance_after: Includes 12,800 restricted stock units.

SEC source: 0000950170-24-054694 · ownership.xml · derivative · entry 4

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 370,000

Underlying: Common Stock · 370,000 shares

Expires 2033-03-01

F3 · derivative.exercise_price: The exercise price of the stock option award is $3.03 per share, representing the fair market value per share of the Issuer's Common Stock on the Effective Date. Under the terms of the stock option award repricing, a repriced stock option award will revert to its original exercise price if exercised during the Retention Period. The "Retention Period" commenced on the Effective Date and ends upon the earliest of (i) the one-year anniversary of the Effective Date, (ii) a Sale Event (as defined in the 2021 Plan), (iii) the termination of the Reporting Person's Service Relationship (as defined in the 2021 Plan) by the Company other than for Cause (as defined in the 2021 Plan) or due to the Reporting Person's death or disability, and (iv) the termination of the Reporting Person's Service Relationship for Good Reason (as defined in the Reporting Person's employment agreement).

F1 · kind: On May 3, 2024, pursuant to the terms of the Issuer's 2021 Stock Option and Incentive Plan (the "2021 Plan"), the Issuer's Board of Directors approved a stock option award repricing, effective as of May 3, 2024 (the "Effective Date"). Except for the new exercise price (see footnote 3 below), all of the other terms of the stock option award remain unchanged. This transaction is exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F4 · derivative.exercise_date: This stock option award was issued pursuant to the 2021 Plan and shall vest and become exercisable in forty-eight (48) equal monthly installments, with the first installment having vested on April 1, 2023.

SEC source: 0000950170-24-054694 · ownership.xml · derivative · entry 3

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 370,000 shares

Expires 2033-03-01

F1 · kind: On May 3, 2024, pursuant to the terms of the Issuer's 2021 Stock Option and Incentive Plan (the "2021 Plan"), the Issuer's Board of Directors approved a stock option award repricing, effective as of May 3, 2024 (the "Effective Date"). Except for the new exercise price (see footnote 3 below), all of the other terms of the stock option award remain unchanged. This transaction is exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F4 · derivative.exercise_date: This stock option award was issued pursuant to the 2021 Plan and shall vest and become exercisable in forty-eight (48) equal monthly installments, with the first installment having vested on April 1, 2023.

SEC source: 0000950170-24-054694 · ownership.xml · derivative · entry 2

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 282,000

Underlying: Common Stock · 282,000 shares

Expires 2032-03-01

F3 · derivative.exercise_price: The exercise price of the stock option award is $3.03 per share, representing the fair market value per share of the Issuer's Common Stock on the Effective Date. Under the terms of the stock option award repricing, a repriced stock option award will revert to its original exercise price if exercised during the Retention Period. The "Retention Period" commenced on the Effective Date and ends upon the earliest of (i) the one-year anniversary of the Effective Date, (ii) a Sale Event (as defined in the 2021 Plan), (iii) the termination of the Reporting Person's Service Relationship (as defined in the 2021 Plan) by the Company other than for Cause (as defined in the 2021 Plan) or due to the Reporting Person's death or disability, and (iv) the termination of the Reporting Person's Service Relationship for Good Reason (as defined in the Reporting Person's employment agreement).

F1 · kind: On May 3, 2024, pursuant to the terms of the Issuer's 2021 Stock Option and Incentive Plan (the "2021 Plan"), the Issuer's Board of Directors approved a stock option award repricing, effective as of May 3, 2024 (the "Effective Date"). Except for the new exercise price (see footnote 3 below), all of the other terms of the stock option award remain unchanged. This transaction is exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the 2021 Plan and shall vest and become exercisable in forty-eight (48) equal monthly installments, with the first installment having vested on April 1, 2022.

SEC source: 0000950170-24-054694 · ownership.xml · derivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 282,000 shares

Expires 2032-03-01

F1 · kind: On May 3, 2024, pursuant to the terms of the Issuer's 2021 Stock Option and Incentive Plan (the "2021 Plan"), the Issuer's Board of Directors approved a stock option award repricing, effective as of May 3, 2024 (the "Effective Date"). Except for the new exercise price (see footnote 3 below), all of the other terms of the stock option award remain unchanged. This transaction is exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the 2021 Plan and shall vest and become exercisable in forty-eight (48) equal monthly installments, with the first installment having vested on April 1, 2022.

SEC source: 0000950170-24-024094 · ownership.xml · derivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 463,000

Underlying: Common Stock · 463,000 shares

Expires 2034-03-01

F1 · derivative.exercise_date: This stock option award was issued pursuant to the Issuer's 2021 Stock Option and Incentive Plan and the shares subject to this stock option shall vest and become exercisable in forty-eight (48) equal monthly installments, with the first installment vesting on April 1, 2024.

SEC source: 0000905148-24-000533 · form4.xml · derivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 32,500

Underlying: Common Stock · 32,500 shares

Expires 2034-02-07

F1 · derivative.exercise_date: The shares subject to the option shall vest in 36 substantially equal monthly installments beginning on February 8, 2024 ("Vesting Commencement Date"), such that all shares are fully vested on the third anniversary of the Vesting Commencement Date, in each case subject to the Reporting Person's continuous service through each such vesting date.

SEC source: 0000950170-23-065228 · ownership.xml · nonDerivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 207,687

F1 · price: The price reported in Column 4 is a weighted average price. The shares were purchased in multiple transactions at prices ranging from $3.67 to $3.79, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price at which the transactions were effected.

SEC source: 0001209191-23-040333 · doc4.xml · derivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,950,000

Underlying: Common Stock · 1,950,000 shares

Expires 2033-06-22

F1 · date: This option award is contingent upon receiving stockholder approval of the amendment and/or restatement of the 2016 Equity Incentive Plan to increase the number of shares available for issuance thereunder.

F2 · derivative.exercise_date: The stock option vests and becomes exercisable in 12 equal monthly installments beginning on July 22, 2023, or on the date of the next annual meeting of stockholders, if earlier, subject to the continuing service of the Reporting Person on each vesting date.

SEC source: 0000899243-23-007030 · doc4.xml · derivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 370,000

Underlying: Common Stock · 370,000 shares

Expires 2033-03-01

F1 · derivative.exercise_date: The shares subject to this option shall vest and become exercisable in forty-eight (48) equal monthly installments, with the first installment vesting on April 1, 2023.

SEC source: 0001628280-22-016849 · wf-form4_165489424153991.xml · derivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 28,700

Underlying: Common Stock · 28,700 shares

Expires 2032-06-07

F1 · derivative.exercise_date: The shares subject to this option vest and become exercisable in full on the earlier of (i) the first anniversary of the date of grant and (ii) the date of the Issuer's next annual meeting of stockholders, subject to the Reporting Person's continuous service to the Issuer through such date.

SEC source: 0001209191-22-035686 · doc4.xml · derivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 43,000

Underlying: Common Stock · 43,000 shares

Expires 2032-06-06

F1 · derivative.exercise_date: The stock option vests and becomes exercisable in 12 equal monthly installments beginning on July 7, 2022, or on the date of the next annual meeting of stockholders, if earlier, subject to the continuing service of the Reporting Person on each vesting date.

SEC source: 0000899243-22-016532 · doc4.xml · nonDerivative · entry 2

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 203,687

F2 · price: The price reported in Column 4 is a weighted average price. The shares were purchased in multiple transactions at prices ranging from $3.89 to $4.00, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price at which the transactions were effected.

SEC source: 0000899243-22-016532 · doc4.xml · nonDerivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 202,687

F1 · price: The price reported in Column 4 is a weighted average price. The shares were purchased in multiple transactions at prices ranging from $3.27 to $3.79, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price at which the transactions were effected.

SEC source: 0000899243-22-009055 · doc4.xml · derivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 282,000

Underlying: Common Stock · 282,000 shares

Expires 2032-03-01

F1 · derivative.exercise_date: The shares subject to this option shall vest and become exercisable in forty-eight (48) equal monthly installments, with the first installment vesting on April 1, 2022.

SEC source: 0001062993-21-012057 · form4.xml · derivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 14,000

Underlying: Common Stock · 14,000 shares

Expires 2031-11-30

F1 · derivative.exercise_date: The option becomes exercisable in equal monthly installments over one year from the date of grant.

SEC source: 0001209191-21-039229 · doc4.xml · derivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 40,000

Underlying: Common Stock · 40,000 shares

Expires 2031-06-07

F1 · derivative.exercise_date: The stock option vests and becomes exercisable in 12 equal monthly installments beginning on July 8, 2021, or on the date of the next annual meeting of stockholders, if earlier, subject to the continuing service of the Reporting Person on each vesting date.

SEC source: 0001273636-20-000013 · edgar.xml · derivative · entry 1

Magovcevic-Liebisch Ivana · CIK 0001279281 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 12,000

Underlying: Common Stock · 12,000 shares

Expires 2030-12-16

F1 · derivative.exercise_date: The option becomes exercisable in equal monthly installments over one year from the date of grant.

SEC source: 0001209191-20-035517 · doc4.xml · derivative · entry 1

Magovcevic Ivana · CIK 0001279281 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 28,100

Underlying: Common Stock · 28,100 shares

Expires 2030-06-07

F1 · derivative.exercise_date: The stock option vests and becomes exercisable in 12 equal monthly installments beginning on July 8, 2020 until such time as the option is 100% vested, subject to the continuing service of the Reporting Person on each vesting date.

SEC source: 0001273636-19-000047 · edgar.xml · derivative · entry 1

Magovcevic Ivana · CIK 0001279281 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,000

Underlying: Common Stock · 10,000 shares

Expires 2029-12-04

F1 · derivative.exercise_date: The option becomes exercisable on December 4, 2020.

SEC source: 0001567619-19-013071 · doc1.xml · derivative · entry 1

Magovcevic Ivana · CIK 0001279281 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 12,400

Underlying: Common Stock · 12,400 shares

Expires 2029-06-06

F1 · derivative.exercise_date: The stock option vests and becomes exercisable in 12 equal monthly installments beginning on July 7, 2019 until such time as the option is 100% vested, subject to the continuing service of the Reporting Person on each vesting date.

SEC source: 0001273636-18-000071 · edgar.xml · derivative · entry 1

Magovcevic Ivana · CIK 0001279281 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,000

Underlying: Common Stock · 10,000 shares

Expires 2028-11-15

F1 · derivative.exercise_date: The option becomes exercisable on November 15, 2019.

SEC source: 0001273636-18-000032 · edgar.xml · derivative · entry 1

Magovcevic Ivana · CIK 0001279281 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 8,000

Underlying: Common Stock · 8,000 shares

Expires 2028-07-25

F1 · derivative.exercise_date: The option becomes exercisable on July 25, 2019.

SEC source: 0001273636-18-000042 · edgar.xml · derivative · entry 1

Magovcevic Ivana · CIK 0001279281 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,000

Underlying: Common Stock · 10,000 shares

Expires 2028-07-25

F1 · shares: This Form 4 is being amended to correct a scrivener's error with regards to the number of shares underlying the option grant.

F2 · derivative.exercise_date: The option becomes exercisable on July 25, 2019.

F1 · derivative.underlying_shares: This Form 4 is being amended to correct a scrivener's error with regards to the number of shares underlying the option grant.

SEC source: 0001140361-18-014889 · doc1.xml · derivative · entry 1

Magovcevic Ivana · CIK 0001279281 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 36,800

Underlying: Common Stock · 36,800 shares

Expires 2028-03-21

F1 · derivative.exercise_date: The stock option vests and becomes exercisable in 36 equal monthly installments beginning on April 22, 2018, until such time as the option is 100% vested, subject to the continuing service of the Reporting Person on each vesting date.

SEC source: 0000899243-17-006161 · doc4.xml · derivative · entry 1

Magovcevic Ivana · CIK 0001279281 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 8,000

Underlying: Common Stock · 8,000 shares

Expires 2027-02-28

F1 · derivative.exercise_date: Option becomes exercisable on February 28, 2018.

SEC source: 0000899243-16-033794 · doc4.xml · nonDerivative · entry 1

Magovcevic Ivana · CIK 0001279281 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,000